from the "Late Night with Conan O'Brian" show. Standard insult given by Triumph, The Insult Comic Dog. Used at the end of a sentence to change a comment/statement/compliment into an insult or put-down. Notice the context of the sentence examples to see how to use it (or decline to use it.)

good time to use it: Oh yes, I just bought your new CD, Ashlee, and it is the greatest thing in the world.....FOR ME TO POOP ON!
bad time to use it: Mom, can you make some Rice Krispies treats......FOR ME TO POOP ON? *gets smacked by Mom, then Dad, then by the rest of the family*